Crane



July 18, 1950 H. J. KING ET AL CRANE 5 Sheets-Sheet l Filed Oct. 2'7, 1944 July 18, 1950 H. J. KING ET AL CRANE 5 sheets-sheet 2 Filed Oct. 27, 1944 Illllllllllllll INVENTOR Hawaralzfmg Ge orgeA Jacobi July 18, 1950 H. J. KING ET Al.

CRANE 5 Sheets-Sheet 3 Filed Oct; 27, 1944 .L b my 0 M O C l ME a V md A r 6 a y w r f 0 .f2 imm. b .N mw Q. WN uw m., 10N. NN o, @www C Nm ruvt .WSH

July n18, 1950 H. J. KING ET A1.

5 Sheets-Sheet 4 CRANE Filed oct. 27, 1944 5 iff 5 14 21 i!! 19- l!! /l/ 25 17k/ 2,6 J8 ,4f f' l ,f4/9 3 12 /H ZU 1923,', 7 FLg 27 Z4 @2f/Z lNvEN-rons Howard J Eng George. Jacob/L' July 1s, 195o H. J. KING ETAL CRANE Filed oct. 27, 1944 5 Sheets-Sheet 5 INVENTOR: Howard .,7. King Patented July 18, 1950 UNITED lS TATES `PAT ENT OF FICE CRANE `Howard J. King, Wilkinsburg, and George A. Jacobi, Moon Township,yAllegheny County, -`Pa., assignors to Dravo Corporation, Pittsburgh, Pa., :a corporation of Pennsylvania v :ApplicationOctober 27, 1944, Serial No. 560,576

12 claims. (Ciara-"3) `it is desirable to lower :the crane below its maximum reach,` or lowermostwoperating position, either for lashing `theijib dow-n so-that it cannot whip or move `about when the Iboat or `'barge is being v'moved from one `position to another, or so that it will Aclear bridges or -other structures.

Alsoin apparatus of this kind, whether the derrick or crane be on a barge or be on land, :it is desirable to lower the boom lor jib below its lower normal limit of movement for vvstorage or repairs.

In conventional cranes of this type, it is the practice to `extend `the voperating mechanism,`

through which th'e jib is raised or lowered, so as to `allow for thelfull desire'drange of movement of the jib even to the lowered or storing position. This, particularly in large, heavy cranes,

increases4 considerablythe cost of the operating mechanism, the weight `of the mechanism, Yand may create an inconvenient geometrical arrange- 'ment in the design of'the crane.- Normally, in use, the boom oriib is swung from its. position of minimum reach, i. e., where it is most nearly vertical, to' its position of maximum reach, i. e., iii the operating position at which it is mostvnearly horizontal. This is usually an arc of somewhat less than 90; To lower or drop they jib several degrees below its` position of maximum reach at the present time-requires thatthewoperating -mechanism becapab'l'e of swingingithe boom or jib Vnot onlythro'ugh its normal operatingrange, but also an additional distancewhereby the overall movement may be through an arc in excess;

of 90. This 'operating `,mechanism is heavy,

cumbersome, and expensive,` and since the por- -tion which permits the extended range of movement is only 'used at such occasional times as the boom is being lowered into position for storing-or repairs, or r'aised'fromtsuch a lowered position, a considerable increased mass of expensive machinery is thus providedffor transient and momentary situations According to the present invention,` there isr providedD an arrangementl in which theu mechanism for raising and lowering tlielboiorniwill` have an operating' range only 'sufficient to. move the boom' or jib in theu range between its positions ofimaximum andy minimum reach; ,-Tolower the jib `to a position for storage or repairs, our invention provides a hinge structure or section in.

,the jib adjacent the base operably interposed between the main portion of the jib and the operatingy mechanism with a releasable and extensible connection which can be utilized in effecting an auxiliary `movement of the jib Vfrom its position of4 maximumreach to a lowered position for storage and repairs. vThe hinge in the jib or boom structure is normally inactive, because of the presence of a rigid linlagethat prevents relative movement between the hinged portions, yand the ib thus normally functions as a completely rigid boom.A nHowever, when it is to be lowered beyond its operating range, provision is made vfor independently supporting the main portion vof the jib whilethereleasable linkage is disconneotedzand the inner part of the jib is separately moved by the jib `operating mechanism relative to the main section of the jib, and-thus change the angular relation between the two secl" tions. this relative movement of the two parts of the jib takes place, an extensible linkage comes into operation, coupling the usections in their new relatio'nl Then by again operating the jib operating mechanism in a direction to lower the jib, the jib as a Whole will move, and the outer ii'ortion of the jib will lower from the position of maximum reach to a position for storing and repairing the jib. Thus while the voperating mechanism is capable of moving the jib through an arc somewhatless than 90?, the hinge arrangement permitting a change in the angular relation of the vtwo parts of the jib enablesthe jib to be effectively moved through a much greater arc. Y Y ur invention therefore reduces considerably the cost of the operating mechanism, its weight,

and lsiifleuries the problems of design, whiie the hinge lin the boom is a negligible item in over-all cost ofthe cranes g n Y Our invention may beA more fully understood by reference to the accompanying drawings, in which: l y V n Fig. l` is a more or less conventional illustration of a crane of the type to which the present invention relates, showing in full Vlines the position of the boom or jib at maximum reach, the dot-and-dash lines showing the position of the `jib when it is at a position ofrminimum reach, and the dotted lines showing the jib lowered for storage;

Fig.- 2 is a front elevation of the construction shown in Fig. 1;

Fig 3 is a fragmentary View on a 1arger scale showing in greater detail, but still more or less schematically, the construction at the base of the jib and the operating mechanism;

Fig. 4 is a line drawing showing the jib in the position of minimum reach;

Fig. 5 is a similar view showing the jib in the position of maximum reach;

Fig. 6 is a view similar to Fig. 5, showing the rst step toward lowering the jib beyond the position of maximum reach to a storage position, with the cable attached to the movable outer section;

Fig. '7 is a similar View in which the jib has been again lowered to bring special cables which are at this time brought into play, taut;

Figs. 8 and 9 are detailed views of the upper part of the hinged portion of the jib with the cables in position, Fig. 8 showing the wedge blocks still in place between the two sections of the jib, and the temporary linkage in position, whereas in Fig. 9 the wedge blocks are removed and the said links are disconnected;

Fig. 10 is a schematic view showing the equalizer through which the temporary cables are connected, the view being generally a schematic view;

Fig. 11 shows a succeeding step in which the extensible linkage between the hinged parts of the jib has come into play, and the jib has been raised slightly to slacken the tension on the temporary cables; and

Fig. 12 shows the jib lowered to a position for storage or repairs, the temporary cables at this time having been disconnected.

In the drawings we have disclosed one particular type of crane with a screw type of operating mechanism for moving the jib through a vertical arc. It lwill be understood, however, that this is purely'by way of illustration, and that the invention is applicable to various types of cranes, and

with various types of operating mechanisms.

Referring now to the specific construction disclosed in the drawings, there is disclosed in Fig. 1 a support such as the boat or barge 2 on which is a platform 3 carrying a turret or turntable 4 on which is a super structure 5. Pivotally mounted on the turntable. to move in a vertical arc, is a jib or boom designated generally as 6, and which has its pivotal support on the turntable at 'I, the pivot point 1 as best shown in the schematic figures. as for example Fig. 4, being at the inner end of the boom which is of a generally triangular truss form.

The crane generally is of a more or less conventional construction, except for the features to be hereinafter described. Instead of the jib being a unitary member, as has heretofore been the common practice, the jib of the present invention may be considered as having two parts, comprising a main boom or jib portion 8, and an auxiliary or base portion 9, the base portion being pivotally hinged to the main portion at I0. The main portion 8 has an inner end frame structure II, and the base portion 9 has a normally substantially parallel frame structure I2, the pivot I0 providing a pivoted connection between these two frame structures.

The base portion 9 has a second frame structure I3 which diverges from the frame structure I2, and as best shown in Fig. 3, the members I2 and I3 are connected at their upper and outer ends by a connecting structure I4, so that the inner auxiliary jib section 9 is of generally triangular form. The connecting portion I4, it will be perceived, forms in effect a continuation of .4 the upper chord of the truss-like structure of the jib portion 8.

The crane operating mechanism may be of any well known or preferred type. In the drawings, the operating mechanism is designated generally at I5. It' comprises a rigid frame structure having its lower end pivotally mounted on the turntable at I6. It is provided with a longitudinally extending screw shaft I'I that is driven by a motor and reducing gear I8. A nut I9 is slideably and non-rotatably mounted in the frame I5, and this nut is provided with trunnions 20 which pivotally engage the frame member I4.

The motor I8, which is a reversible motor, serves to drive the screw shaft in either direction, and the turning of the screw shaft causes the nut I9 to move back and forth along the frame I5. This in turn raises and lowers the jib and the range of movement of the jib is limited to the length of travel of the nut I9 on the shaft I1. A mechanism of this general type is shown in Patent 2,188,686 of January 30, 1940.

In order that the two sections of the jib 8 and 9 will be rigidly connected in the normal operation of the crane, the frame structures I I and I2 are normally coupled together by short links 2I. These links are permanently mounted on pins 22 at the upper end of the frame structure I I of the main jib section. They have slotted end portions 23 which loosely engage over pins 24 at the top of the frame structure I2 of the auxiliary jib section. These links normally connect the two portions 8 and 9 against relative movement about the hinge or pivot IIJ so that when the nut' I9 of the operating mechanism is moved back and forth, the whole jib moves as a rigid unit. Wedge blocks 21 may be placed between the two frame structures I I and I2 during the normal operation of the crane to avoid any looseness in thelinkage between the two parts of the jib.

In addition to the short links 2|, there are folding or toggle links 25 which are pivoted to each other at 26, and which have their ends engaging the pins 22 and 24. These toggle links form an extensible linkage which can be opened out when the short links 2I are operated to uncouple the two sections of the jib, the toggle linkage then serving to limit the relative movement between the two sections of the jib, and to provide in effect an extension or elongation of the upper chord of the truss-like structure of jib portion 8, as may be understood upon considering Figs. 11 and 12. l

Firmly anchored on the turntable, as best shown in Fig. 10, are two clevices designated 28. Each clevice 28 carries a bell crank 29. The parallel longitudinal arms of the two bell cranks are connected by a cross-linkage 30, and the other arms of each bell crank carry an equalizer 3I. To each end of each equalizer is connected a fixed length of cable 32, and each of these cables, as best shown in Figs. 8 and 9, is provided with a clevice 33 at its outer end, which clevice is designed to be engaged over one of the pins 22. These cables are used in the manner hereinafter described, and the bell cranks and equalizers provide an equalizing system for equalizing the strain on the several cables.

In operation the crane normally swings from the minimum reach position, in which the jib is most nearly vertical, and which is shown in Fig. 4, to the maximum reach position in which the jib approaches most nearly a horizontal position. This movement of the jib between the maximum and minimum reaches is of course accomplished Kapitn? distance which the nut IB may travelonothe threaded. shaft l The range `of{ jmovement-permitted by -the 'nut jl 9` ris sufiicientforfall Pnormal conditions of ,operationv `of lthe crane.-' However,

as shown -indotted Alines i'nlFig. Land as shown schematically viniFig'. '112, it `is desirableatjtimes to `lower'theiboom:below the yposition of maxi mum reach shown in fFigN toaipoition where it can be stored oritransitlortadl "eloz move Ithe jib to this npQsitiorn-theoperatori-lijst 'operates the crane to bring'the jib, in the positionl ofimaximumA reach showninFig. 5.""I,tfwillbe noted at' 6 and attaches the clevices 33 on the cables 32" to the pins 22. In Fig. the several cables are indicated as being so attached to the pins. Then fthe boom `is lowerediagain-toward its-position of maximum reach until the cables 32 become taut,

as indicated in Fig. 7, andthe .links 2l are dis-iy engaged from the pins 24. vAs soon as this is e. done, .the jib is held in the position of,maximum .operating reach by the cables 32, andthe inner `end section o'f the jib 9` is free to move about .the hinge lll. The operating mechanismis .then

operated .to move the' inneri end gsection' .9 in the direction in' which 'it normally '.wouldinove to `raise the' crane toward the position of minimum lreach, the `nut IS travelingxdown thescrew I1 untiljthe'toggle'levers 25 are` opened straightout;

as .shown in Fig. 11, and'movement in thisLcondivtion is continued, whereuponthe toggle levers,

becoming straight, start toliftthe outer end of the jib. When-the outerend of the jib has been lifted slightly, the cables 32 will becomeslack, asf VshowninrFig. 11, andthe-cables can loe-disconl' nected from the pins` 22.

Following the disconnection of the cables, the operating mechanism may then be reversed, causing the nut i9 to travel up the screw I1 and lower the boom to the position shown in Fig. 12.

It will thus be seen that by forming the jib in two sections hinged together in the manner indicated, the angular relation between the two sections of the jib can be changed, making it possible for an operating mechanism which is effective through a very limited arc of movement to effect the movement of the jib through an arc of 90 or more. Since the operation of lowering the boom or jib to the position shown in Fig. l2, or lifting it from this position usually takes place at infrequent intervals, the manipulation herein described is not one which has to be frequently performed, nor one which would involve serious delay.

In raising the jib back to an operating range of positions, the operations previously described are performed in reverse order. It might be noted that the operating mechanism comprising the screw and the nut is one that is Well known in the art and forms no part of the present invention, and it might also be pointed out that there is a second nut I9' on the lower part of the screw, and the pivotal connection between the operating mechanism and the platform is effected through this nut so that the nuts i9 and it move toward and away from each other simultaneously.`

While We have illustrated and described one specic embodiment of our invention, it will be understood that this is by way of illustration, and

` "that various;changesandmodiicationsaref within the "contemplation ofrournvention and yunder "the Yscopefofthefollowing claims. f "We Aclaim:

"1. yIn a vcraneofthe-typehaving a jibmounted infor .movementiina-vertical arcandV having an operating mechanism for'moving the jib, Athe in- `verition"hereindescribedcomprising a connection j iriterposedibetween the operating--mechanismfand 10 i "the fjib, whichjjconnection Yincludes ymeans--for [varying the iangularrelation between-the jib and "the operating mechanism, and `meansv `fortem- `porarily supporting the jib when ra change insuch angular relation is beingeffected.

"2 In aA crane of the 'typehaving a `jib mounted `for`4 movement in'a vertical arcrand havingI an operating mechanism'for-moving the jib, thein- "vention `hereindescribedv comprising a connection i' interposed` between-the operating mechanism 'and 'V the jibrvvhich connection includesmeans for vary- "ing theangular relation betweenthe jib-and the `operating mechanism, `and means for temporarily "supportingthe jib whena change in such angular relation is vbeing effected-said means comprisfing a'plurality'of cablesv deta-chably secured to the jib pand 1connected to an anchorage through an i equalizing` system.

3. Apparatus ofthe character described including in ,combination a main boom pivoted at its lower end, an auxiliary `boom, pivoted at its lower end at vsulcstantially the pivot 'point of the main mentfof the 'auxiliary booml independent of the mainboom when said detachable connection is remix/ed,V and l power actuating means connected ,with said auxiliary boom whereby to selectively P' rnovepeitherthe entire boom structure `including "the main and auxiliary` boom, or the auxiliary "boomjindependent ofthe mainboom.

4. :Apparatus asjdened in claim 3 and in- A cluding a temporary holdingor stay means, interposed between the main boom and a xed support, to hold the main boom in fixed position during any period of independent movement of said auxiliary boom.

5. A boom construction for cranes and the like comprising a main boom section hingedly supported for movement in a vertical arc, an auxiliary boom structure of triangular formation pivotally secured to the inner end of the main boom section and movable in a vertical arc relative to the main boom section, detachable link- `age normally holding the main boom section and auxiliary boom structure against relative movement, and an operating mechanism connected with the auxiliary boom structure.

6. A boom construction having a pivotally mounted inner section, an operating mechanism positively geared to said section for swinging it in a vertical arc, a relatively long outer boomv section normally extending rigidly outward from said inner section, and an extensible coupling between said boom sections providing for the angular adjustment of one section relatively to the other.

7. A boom construction having an inner section pivotally mounted for swinging in a vertical arc, an operating mechanism connected to said inner section at a point spaced from the pivotal mounting thereof for swinging the section in said aro, a relatively long outer boom section normally extending rigidly outward from said inner section, and an extensible coupling between said ment of one section relatively to the other.

8. A crane construction comprising a base and a boom mounted thereon, said boom comprising an inner boom section and an outer boom section severally mounted to swing in a vertical plane, operating means connected to lthe inner boom section for swinging it relatively to Vsaid base, and means for normally connecting4 said boom sections to swing as a unit under the effect of said operating means on said inner section, said connecting means being releasable to permit said operating means to swing said inner section relatively to said outer section.

9. A crane construction comprising a base and a boom mounted thereon, said boom comprising an inner boom section and an outer boom section severally mounted to swing in a vertical plane, operating means connected to the inner boom section for swinging it relatively to said base, and means for normally connecting said boom sections to swing as a unit under the effect of said operating means on said inner section, said connecting means being releasable to permit said operating means to swing said inner section relatively to said outer section, together with means for limiting the swing of the inner boom section relatively to the outer boom section.

10. A crane construction comprising a base and a boom mounted thereon, said boom comprising an inner boom section and an outer boom section severally mounted to swing in a vertical plane, operating means connected to the inner boom section for swinging it relatively to said base, means for normally connecting said boom sections to swing as a unit underV the e'ect of said operating means on said inner section, said means being releasable to permit said operating means to swing said inner section relatively to said outer section, said outer boom section comprising a jib and said inner boom section comprising a frame structure hinged to the inner endof said vjib, and means effective between said -frame structure and said jib for limiting the swing of said frame structure relatively to said jib.

5 11. Av crane having a jib, an operating mechanism for the jib, an auxiliary jib section at the inner end of the jib and coupled to said operating mechanism for effecting the swing of the jib, a releasable coupling between the jib and the auxiliary jib, and an extensible coupling effective angular movement relatively to said outer portion, an extensible coupling between said inner and outer portions, and a boom swinging mechanism connected to said inner portion.

HOWARD J. KING.

GEORGE A. JACOBI.l

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 503,362 Biehn Aug. 15, 1893 1,093,656 Sidwell Apr. 21, 1914 3o 1,342,480 Welin June 8, 1920 1,481,351 Cochran Jan. 22, 1924 1,560,194 Armstrong Nov. 3, 1925 1,598,723 Holmes Sept. 7,1926 1,629,592 Staley May 24, 192.7 2,019,938 Stephens Nov. 5, 1935 2,110,753 Zeilman Mar. 8, 1938 2,198,793 Schroeder Apr. 30, 1940 2,374,045 Soucia Apr. 17, 1945 FOREIGN PATENTS Number Country Date 2622317 Great Britain Dec. 9, 1926 470,295 Great Britain Aug. 12, 1937 

